Epimegabenthos based on seafloor georeferenced mosaics of the Hornsundbanken methane seep area

Occurrence
Latest version published by The University Centre in Svalbard on May 12, 2026 The University Centre in Svalbard
Publication date:
12 May 2026
License:
CC-BY 4.0

Download the latest version of this resource data as a Darwin Core Archive (DwC-A) or the resource metadata as EML or RTF:

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Description

This dataset consists of all the epimegabenthic fauna marked and enumerated from two seafloor georeferenced image mosaics from the shelf off Svalbard's Hornsund fjord (Hornsundbanken). Videos of the seafloor were obtained with the the remotely operated vehicle (ROV) Ægir from the research vessel Kronprins Haakon, maintaining an altitude of between 1 and 1.5 m. Images were extracted every 3 seconds via the free software ffmpeg and using the images and their associated navigation data, georeferenced mosaics were generated with Agisoft's Metashape software. The two mosaics cover areas of 282 m2 and 164 m2 (446 m2 combined). The mosaics were inputted into Arc Desktop and using the Editor tool, all fauna were identified, marked and enumerated. All individuals were marked to obtain numbers for each taxon. Colonial or encrusting animals were outlined to obtain areal coverage. Identifications were made to the lowest possible level which was species in many cases, but only phylum in some cases. The faunal data from these mosaics were used in the publication by Sen et al. Fauna of shallow water Arctic seep not driven by water masses currently under review.

Data Records

The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 68 records.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Sen A, Caudan C, Rodés N, Hong W L, ten Hietbrink S, Szymczycha B, Diak M, Broms F, Knies J (2026). Epimegabenthos based on seafloor georeferenced mosaics of the Hornsundbanken methane seep area. Version 1.1. The University Centre in Svalbard. Occurrence dataset. https://ipt.gbif.no/resource?r=epimegabenthos_hornsundbanken_seep&v=1.1

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is The University Centre in Svalbard. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 11cd1b4f-0d2e-418b-8b22-5e00f2308187.  The University Centre in Svalbard publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF Norway.

Keywords

Occurrence

Contacts

Arunima Sen
  • Author
  • Associate Professor
The University Centre in Svalbard (UNIS)
Longyearbyen
NO
Corentin Caudan
  • Originator
  • student
Sorbonne University
Nil Rodés
  • Originator
  • engineer
The University Centre in Svalbard (UNIS)
Wei Li Hong
  • Originator
  • Associate Professor
Stockholm University
Sophie ten Hietbrink
  • Originator
  • student
Stockholm University
Beata Szymczycha
  • Originator
  • Associate Professor
Institute of Oceanology Polish Academy of Sciences (IOPAN)
Magdalena Diak
  • Originator
  • Researcher
Institute of Oceanology Polish Academy of Sciences (IOPAN)
Fredrik Broms
  • Originator
  • Researcher
North Norwegian Humpback Whale Catalogue (NNHWC)
Jochen Knies
  • Originator
  • Researcher
Norwegian Geological Survey (NGU), iC3: Centre for ice, Cryosphere, Carbon and Climate
Arunima Sen
  • Author
  • Associate Professor
The University Centre in Svalbard (UNIS)
Longyear
NO

Geographic Coverage

Continental shelf off the Hornsund fjord of Svalbard, known as Hornsundbanken

Bounding Coordinates South West [76.791, 14.159], North East [76.793, 14.168]

Taxonomic Coverage

N/A

Phylum Chordata, Mollusca, Arthropoda, Porifera, Nemertea, Cnidaria, Annelida, Echinodermata

Temporal Coverage

Start Date 2023-03-06

Project Data

Epimegabenthic fauna marked in a GIS (Geographic Information System) from two georeferenced mosaics constructed from still images obtained from ROV (remotely operated vechicle) video.

Title Epimegabenthos based on seafloor georeferenced mosaics of the Hornsundbanken methane seep area
Funding Arctic SGD (Submarine groundwater discharge) project (The Norwegian Financial Mechanism 2014-2021, project number 019/34/H/ ST10/00645 and 2019/34/H/ST10/00504).

The personnel involved in the project:

Arunima Sen
  • Author

Sampling Methods

Numerous gas flares (gas bubbles escaping from the seafloor) have been detected acoustically on the shelf off the Hornsund fjord of Svalbard (known as Hornsundbanken). Using the remotely operated vehicle (ROV) Ægir from the research vessel Kronprins Haakon, video of the seafloor was recorded, maintaining an altitude of about 1-1.5 m. The HD video camera of the ROV was facing directly downwards (perpendicular to the seafloor) for the imaging process. Video acquisition was performed in a lawn-mower pattern, ensuring at least 25% overlap between adjacent lines. Images were extracted from the video every 2 seconds using the free software, ffmpeg. Navigation coordinates for each image were obtained from the ROV's track. These images were stitched together to create a single, composite georeferenced image (mosaic) of the seafloor. For this, structure-from-motion photogrammetry processing was conducted using Agisoft Metashape (version 2.0.2, build number 16334). Two digital models were constructed, covering a total area of 446 m². The georeferenced mosaics were imported into ArcMap Desktop version 10.8.2 and all visible fauna were marked with the Editor tool. Individual organisms were marked as points (point feature class). Colonial or encrusting organisms were outlined to get areal coverages (polygon feature classes). Identification was done to lowest taxonomic level as possible, which was species in some cases, but often reliable identification was limited to higher levels such as genus or family and in certain cases, only phylum level.

Study Extent Two locations within an area of active methane seepage on the seafloor on the continental shelf off the Hornsund fjord of Svalbard (Hornsundbanken).

Method step description:

  1. Video imaging of the seafloor was conducted via the downward facing HD camera on the ROV. Overlap was maintained between adjacent video lines. Images were extracted from the video every three seconds and in combination with the corresponding navigation data for the images, a single, composite, georeferenced image (mosaic) was created via Agisoft's Metashape software. Two mosaics were generated. The mosaics were inputted into ArcMap Desktop and all visible features and fauna were marked and enumerated.